It was meant to be a vision of how we will all live in future - a smart city built from the internet up - offering citizens the chance to experience the very latest technology.

That would include autonomous cars, innovative ways to collect rubbish and shared spaces for communities to come together in new ways.

Sidewalk Labs, a sister company to Google, had acquired disused land in Toronto, Canada for this bold urban experiment, which it hoped would become a model for other cities around the world.

The fact that it would be collecting a lot of data from sensors placed all around the harbourside development unsettled some.

Now many are asking whether a private firm should take charge of urban improvement at all.
Radical mix

The project was announced to much fanfare in 2017 and the partnership between Sidewalk Labs and Toronto Waterfront, the agency charged with revitalising the area, promised great things.

Led by Dan Doctoroff, ex-deputy mayor of New York, working with a team of both government and digital experts, Sidewalk Labs promised a radical mix of offices, retail and makerspaces with a green agenda, robots and underground waste disposal. It would be, said Mr Doctoroff, a happy place to live.

Mr Doctoroff was due to speak at the TED conference, hosted on the other side of Canada in Vancouver, in April.

He cancelled his appearance at short notice. Meanwhile, back in Toronto, a group of citizens called Block Sidewalk held its inaugural meeting.

And none of the people attending seemed particularly happy, according to organiser Bianca Wylie.

She told the BBC that those gathered had a range of concerns, from the lack of transparency in the way Toronto Waterfront had awarded the contract to Sidewalk Labs, to doubts about whether the firm has a proven track record in delivering such an ambitious project.

There were also concern about what the company was planning to do with the area in the long term.

"This group was formed because leaked documents in the Toronto Star suggested Sidewalk Labs had a far grander vision than the 12-acre (48,500-sq m) site it had talked about. We were concerned that we were not getting transparency," Ms Wylie told the BBC.

The article she refers to alleged that the Google-affiliate wanted to build a much bigger neighbourhood at Quayside and provide new transport for it.

In return for its investment it wanted a share of property taxes, development fees and increased value of city land that would normally go to the city.